Have a old Gibson PA amp that needs repair. No serial or model # anywhere, maybe a prototype or something? Has 2-5881, 1-12AX7, 1-12AY7 , 1-12AU7, 1-OA2 & SS rectified. Looking for schematic or any other info you might have. Thanks.

Looked at a few of the schematics there, but didn't find anything similar to what I have. With no model #, not sure what to look for. Went to another web site that lists the tube compliment of varoius Gibson amps & didn't find anything with the exact tubes this amp uses.